Radar systems, such as those used for surveillance and tracking, must address challenging search and detection tasks for targets in various types of clutter and interference. Many radar systems search large areas of Doppler and space for small targets of interest while at the same time limiting the impact of interference and clutter. These requirements result in an increased number of false detections, which are sorted out in track files and/or detection algorithms. The presence of increased detections also increases the probability of dropping the intended target or tracking the wrong target. Another problem with increased detections is that a radar system may have to increase the number of looks to help discriminate the detections. This increases the time needed to identify a target, which is particularly undesirable for fast moving targets.
Some conventional radar systems address these problems by transmitting two or more complementary waveforms concurrently. These approaches, however, can significantly increase the complexity and cost of the radar system's hardware.
Thus, there are general needs for improved radar systems with reduced hardware complexity. There are also general needs for radar systems that can search large areas of Doppler and space for small targets of interest while at the same time limiting the impact of interference and clutter. There are also general needs for radar systems that generate less false detections. There are also general needs for radar systems with a reduced probability of dropping an intended target or tracking a wrong target. There are also general needs for radar systems that can improve a desired target's signal-to-noise ratio (SNR) and null out unwanted targets without additional transmissions (i.e., looks). There are also general needs for radar systems that can adapt their ambiguity function to current and changing environments.